0
Technical Brief

Dislocation Formation From a Polycrystal Free-Surface

[+] Author and Article Information
Jérôme Colin

Institut P',
Université de Poitiers,
ENSMA,
SP2MI-Téléport 2,
Futuroscope-Chasseneuil Cedex F86962, France
e-mail: jerome.colin@univ-poitiers.fr

Contributed by the Applied Mechanics Division of ASME for publication in the JOURNAL OF APPLIED MECHANICS. Manuscript received July 9, 2018; final manuscript received September 18, 2018; published online October 10, 2018. Editor: Yonggang Huang.

J. Appl. Mech 86(1), 014501 (Oct 10, 2018) (3 pages) Paper No: JAM-18-1392; doi: 10.1115/1.4041549 History: Received July 09, 2018; Revised September 18, 2018

The introduction of a dislocation from the free-surface of a grain A of a polycrystal has been investigated from the theoretical point of view. Assuming two disclination dipoles are lying in a high angle boundary separating the corresponding grain A and a neighbor grain B, the equilibrium position of the dislocation has been determined in the grain A versus the separation distance between the two dipoles, the length and strength of each dipole.

FIGURES IN THIS ARTICLE
<>
Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Fedorov, A. A. , Gutkin, M. Y. , and Ovid'ko, I. A. , 2003, “ Transformation of Grain Boundary Dislocation Pile-Ups in Nano- and Polycrystalline Materials,” Acta Mater., 51(4), pp. 887–898. [CrossRef]
Quek, S. S. , Wu, Z. , Zhang, Y. W. , and Srolovitz, D. J. , 2014, “ Polycrystal Deformation in a Discrete Dislocation Dynamics Framework,” Acta Mater., 75, pp. 92–105. [CrossRef]
Pilling, J. , and Ridle, N. , 1989, “Superplasticity in Crystalline Solids,” The Institute of Metal, London.
Sutton, A. P. , and Balluffi, R. W. , 1995, “Interfaces in Crystalline Materials,” Clarendon Press, Oxford, UK.
Ovid'ko, I. A. , and Sheinerman, A. G. , 2017, “ Grain Boundary Sliding, Triple Junction Disclinations and Strain Hardening in Ultrafine-Grained and Nanocrystalline Metals,” Int. J. Plast., 96, pp. 227–241. [CrossRef]
Mompiou, F. , Caillard, D. , and Legros, M. , 2009, “ Grain Boundary Shear-Migration Coupling—Part I: In Situ TEM Straining Experiments in Al Polycrystals,” Acta Mater., 57(7), pp. 2198–2209. [CrossRef]
Caillard, D. , Mompiou, F. , and Legros, M. , 2009, “ Grain-Boundary Shear-Migration Coupling—Part II: Geometrical Model for General Boundaries,” Acta Mater., 57(8), pp. 2390–2402. [CrossRef]
Bobylev, S. V. , Morozov, N. F. , and Ovid'ko, I. A. , 2010, “ Cooperative Grain Boundary Sliding and Migration Process in Nanocrystalline Solids,” Phys. Rev. Lett., 105(5), p. 055504. [CrossRef] [PubMed]
Picu, R. C. , and Gupta, V. , 1996, “ Singularities at Grain Triple Junctions in Two-Dimensional Polycrystals With Cubic and Orthotropic Grains,” ASME J. Appl. Mech., 63(2), pp. 295–300. [CrossRef]
Reedy, D. , 2011, “ Singular Stress Fields at the Intersection of a Grain Boundary and a Stress-Free Edge in a Columnar Polycrystal,” ASME J. Appl. Mech., 78(1), p. 014502. [CrossRef]
Li, J. C. M. , 1960, “ Some Elastic Properties of an Edge Dislocation Wall,” Acta Metall., 8(8), pp. 563–574. [CrossRef]
Li, J. C. M. , 1972, “ Disclination Model of High Angle Grain Boundary,” Surf. Sci., 31, pp. 12–26. [CrossRef]
Romanov, A. E. , and Vladimirov, V. I. , 1992, “ Disclination in Crystalline Solids,” Dislocation in Solids, F. R. N. Nabarro , ed., Vol. 9, North Holland, Amsterdam, The Netherlands, pp. 191–402.
Nazarov, A. A. , 2013, “ Disclinations in Bulk Nanostructured Materials: Their Origin, Relaxation and Role in Materials Properties,” Adv. Nat. Sci.: Nanosci. Nanotechnol., 4(3), p. 033002. [CrossRef]
Landau, L. D. , and Lifshitz, E. M. , 1970, Theory of Elasticity, Vol. 7, Pergamon Press, Oxford, UK, pp. 27–30.
Hirth, J. P. , and Lothe, J. , 1982, Theory of Dislocations, 2nd ed., Wiley, New York, pp. 59–95.
Peach, M. , and Köhler, J. S. , 1950, “ The Forces Exerted on Dislocations and the Stress Fields Produced by Them,” Phys. Rev., 80(3), pp. 436–439. [CrossRef]

Figures

Grahic Jump Location
Fig. 5

Stability diagram in the (L̃,d̃) plane with respect to the introduction of a dislocation in the grain A for ω = 10 deg, 15 deg, and 30 deg, with h̃=500. In region 1, the dislocation introduction is favorable, in region 2, it is not.

Grahic Jump Location
Fig. 4

Stable equilibrium position p̃eq of the dislocation versus the dipole length L̃, with ω=15 deg, d̃=50, and h̃=500

Grahic Jump Location
Fig. 3

Stable equilibrium position p̃eq of the dislocation versus d̃, with ω=15 deg, L̃=200, and h̃=500

Grahic Jump Location
Fig. 2

Reduced total energy variation ΔẼtot versus the dimensionless dislocation position p̃ for different values of the separation distance between the two dipoles, with ω=15 deg, L̃=100, and h̃=500

Grahic Jump Location
Fig. 1

A high angle grain boundary between two grains A and B is located at a distance h from the free surface of a polycrystalline solid. Two dipoles of disclinations of length L and strength ±ω are introduced in the boundary and are separated of a distance 2d. An edge dislocation of Burgers vector (b, 0) is introduced in the grain A from the free-surface at a position (−p, 0).

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In